Stamatiou will join the social network as an Experience Designer on the Growth Team

Twitter is adding a new member to its design team: Picplum co-founder Paul Stamatiou, who announced that he will be joining the company on his blog Monday.

"I have always wanted to work at Twitter but never actually thought about it until Akash Garg reached out a few months ago. Yes, this is a post announcing that I have joined the flock at Twitter. I signed up for Twitter exactly six years ago in January 2007 as user #624,683," said Stamatiou.

Stamatiou write that he will be an Experience Designer on the Growth Team, lead by Nancy Broden.

"Why this role? Well, after 5 years of startups (yes, this is my first real job) there's one thing I want to get better at — growing products. Being informed about knowing why things failed or worked well and running a myriad of experiments or usability studies to find the best performing design," Stamatiou wrote.

Picplum is a photo printing service that allows users to email or upload their photos to the Picplum website, which will then print and mail the photos to that person's friends and family worldwide. The prints are professionally produced, high-quality photo prints that come in specially-designed packages a few days later.

Picplum was founded by Stamatiou and Akshay Dodeja in as a way to make sharing photo prints a painless and fun experience. The Y Combinator-backed photo-sharing and printing startup debuted in the summer of 2010.

Photos are available in 4x4 or 4x6 for 50 cents a print; 5x5 or 5x7 for $1 a print; and 8x10 for $4 a print.

What happens to Picplum now

Co-founder Akshay already left the company to join Live Nation Labs. So, now that Stamatiou is leaving as well, does this mean the end of Picplum?

Not according to Stamatiou, who says that he will stay onboard in an advisory role and that Akshay "will still be actively maintaining and developing Picplum in his spare time." Meanwhile, the two will be seeking out people to help run Picplum “from marketing to customer support."

Buts its hard to not see the company being left at a disadvantage without strong leadership at the top.

When Instagram was bought for a $1 billion by Facebook, maybe, including me, figured that other photo sharing companies would fare pretty well during the year.

Instead a number of them were either bought up, or shut down entirely, including PicPlz, a similar service to Instagram, in that it allowed users to put filters on their photos, and to see how many users had viewed their pictures,which announced that it would be shutting down in July. In November, another Instagram competitor, Color, the app that organized photos by event and location, said that it would be closing at the end of 2012.

Some have come out better, such as ThisLife ,a cloud-based photo and video organization companywhich, earlier this month, was bought by Shutterfly. But, other than Instagram, none of the photo-sharing startups have been able to rise above the pack.

In such a crowded and competitive field, it will be interesting to see if Picplum can survive with both of its founders leaving it for other projects.

When asked for comment, a Twitter spokesperson pointed me toward this Tweet: